Assuming you're a US citizen, you can bring back 1 liter of alcohol per person. You're allowed to bring back more, but anything above 1 liter is something you will have to pay taxes/duties on. I recommend you double-check the state laws for whichever state you'll first be arriving in - if their law is more restrictive, it prevails.
The general rules for bringing things back into the US are here:

GoCubsGo got it right on his second post... with the additional comment that at least one of those liters of distilled spirits must be produced in the Caribbean Basin. Not subject to the distilled spirits are low alcohol content liquers, such as rum cream. At 17% alcoholic content, this yummy concoction does not qualify as a distilled spirit. It is not unusual for folks to bring back several bottles of this.

GCG's first post is also right on as far as knowing the rules for the state you will be arriving in, as well as your own state. They all apply.

Rum Cream is lower alcohol so you can bring back more, just not sure of how much more. If you purchase at the airport, they will pack for carry on and the then the box they pack it in, usually fits nicely into our checked bag once we get back to our first stop in the states. The dirty clothes go into a soft duffle (gym bag type) that fits nicely around the box.

Hello,
As to the post above it is correct. Unless you are bringing back Rum Cream. The alcohol content is low enough that you can bring back as much as you want as long as it does not look as you are bringing it back to sell. I brought 4 bottles back last time

Just a couple of suggestions. If you are bringing back bottles that you have purchased while in Jamaica, make sure you pack them in your check-in luggage. I have seen many people loose their beautiful bottle of rum at customs.
When packing the bottle wrap it in newspaper, put it in a strong zip lock bag (maybe double bag it) and then put dirty clothes that you wont mind throwing out around the bottle. We've had a bottle break once and this packing method saved all of our clothes from being ruined. Our suitcases often come off the plane looking like they've been through a battle.

Another suggestion: Buy it at the airport!! They are cheaper! ALSO, they pack it up nicely for you to carry on. BUT, if you have a connecting flight in the states, you will have to go through customs and security again before you get on your connecting flight. Therefore, you will have to put your liquids into your luggage.
It sounds as though you are already there, but if you are not: purchase one of those XL ziploc bags to put it in for peace of mind.

I read a great tip on this board regarding liquor in your luggage. Purchase some swim wings at the dollar store (the ones that go on kids arms) and wrap around the bottles before you pack. What a great idea; one that we plan to do on our next trip. We generally use the large ziploc bags and bubble wrap, but lost one bottle last year due to breakage.

I wanted to clarify how much alcohol you can bring back - you can bring back as much as you want but anymore than 2 liters per person OR 5 liters per couple is subject to additional taxes. But we have traveled many times and always brought back more than that and always declared it on our customs forms, but we have NEVER had to pay any taxes. Just always be sure to indicate that it is for personal use. Even if you pay taxes, it won't be that much.

I wanted to clarify how much alcohol you can bring back - you can bring back as much as you want but anymore than 2 liters per person OR 5 liters per couple is subject to additional taxes. But we have traveled many times and always brought back more than that and always declared it on our customs forms, but we have NEVER had to pay any taxes. Just always be sure to indicate that it is for personal use. Even if you pay taxes, it won't be that much.

Two years ago we brought back 5 bottles of rum cream, 3 large bottles (1 liter each) and two small bottles (375 ml each) for a total of 3.75 liters. We ended up having to pay taxes on the bottles when we arrived at DFW.

We flew non-stop from MBJ to DFW and had the rum cream in the boxes packed by the shop in the MBJ airport so it was obvious that we had liquor. They asked how many bottles we had and we told them 5 of low alcohol content (17%) rum cream. Then the guy put a red mark on our customs sheet. Getting to the next point in line, they had us pulled aside into another room where we were again asked about the alcohol. They made us open the boxes so that they could inspect the bottles. We explained that they we're of low alcohol content and were told that that didn't matter. Anyway, I think the taxes came only to around $3 but it did add about another 30 min to the time getting through customs. Good thing that was our final destination and we didn't have to make a connecting flight. If I remember correctly the taxes were lower because it was just rum cream and not a higher content alcohol.

I don't think that this procedure happens to everyone. We have not been asked since then. It seems that year that we got a really grumpy customs agent.